Can a shampoo really ‘thicken’ hair, or is this new class of haircare taking its cue from advertising double-speak?
Thickening shampoos are the latest clickbaity marketing scheme inundating us. Do any of them work? (Empty potato chip bag marketing scheme, by Bermix Studio on Unsplash)
Thicker, Fuller, Better?
Step into a Sephora (or another favorite hair product retailer) and you’ll find a bevy of new and recently revamped products promising to thicken your hair and improve density. Included in the ingredients list? A laundry list of natural extracts or a patented ‘complex’ that the maker claims will deliver on their promise.
Do any of them work? Or are we simply witnessing in real-time the latest hair care trend to flood our shelves with empty promises, leaving us with a smaller bank account balance and decidedly un-thickened hair.
A World of Nuance
Marketing double-speak aside, the good news is that some of the ingredients included in these thickening hair care products can really deliver on improving hair strength, density, and thickness. It’s an exciting product development space in the hair care world that should have your attention. It’s not that people haven’t tried augmenting shampoos, conditioners and serums before (who doesn’t want to add a hair boost to their shower?!), but finding ingredients that could meaningfully deliver the improvements many people are chasing have mostly eluded us — that is until recently.
The catch is that, while these thickening products can work, you need to dig deep into those ingredients lists, because not all of these bespoke complexes are created equal.
Don’t be Misled By Hype
Most of the ingredients found in thickening haircare products are wishful thinking at best, outright misleading at worst. We’re so wrapped up in the marketing claims it’s hard to discern reality from aspirations.
Rosemary oil (the worst offender by far), castor oil (used as a laxative), onion extract (contact dermatitis and teary eyes, hello!), many of the new and novel peptides — none of these will improve your hair calibre or density. In fact, they can make things worse by triggering inflammation and damaging the fragile hair follicle before washing uselessly down the drain (along with your hard-earned money).
Countless experts have widely disproven these ingredients as beneficial for hair, in particular rosemary oil, but in many ways the damage is already done. There’s so much demand from consumers for products containing these kinds of ingredients (placebo testimonials are powerful amplifiers) that product developers… well, they shut their eyes to the research and look the other way.
A few bad players (and papers) have caused countless years and wasted dollars in research and consumer dollars. (Picture of rosemary sprig, Image by Sophie on Unsplash).
Ingredients to Look For that Improve Hair Density and Thickness
The caffeine that’s in your morning cup of coffee? It’s at the top of the list of ingredients to look for in thickening hair care products. Caffeine (the specific form derived from coffee) has been clinically shown to combat thinning hair and promoting growth by stimulating blood flow, neutralizing the root-damaging hormone DHT, and extending the hair’s active growth phase (anagen). In fact, many dermatologists note that topical application of caffeine directly to the hair follicle is more effective than drinking coffee.
Saw Palmetto is another great ingredient to seek out, as it combats hair thinning through its natural DHT blocking activity, the main hormone responsible for thinning. Curcumin, derived from turmeric, also shows promise for improving density, growth, and hair thickness due to its strong anti-inflammatory and antioxidant properties, as well as mild DHT blocking potential. Pumpkin seed oil also shows strong clinical evidence as being beneficial for hair thinning by acting as yet another natural DHT blocker with the added bonus of delivering nourishing fatty acids to the scalp.
Finally, emerging clinical and laboratory data suggest some copper tripeptides (GHK-Cu & AHK-Cu specifically) might help increase improve scalp circulation, stimulate dermal papilla cells in the hair follicle, and prolong anagen phase, all of which is important in supporting growth and density. A recent 2026 clinical study on patients with androgenetic alopecia (pattern hair loss) even showed improved hair density and thickness with topical application.
How to Navigate the Thickening Shampoo Landscape
The best advice when choosing a thickening haircare product? For starters, if it doesn’t include a proven peptide, caffeine from coffee, saw palmetto, curcumin, or pumpkin seed oil extract, take your business and consumer dollars elsewhere. The equally critical thing to look for when considering a product is whether it has been clinically tested. Just because effective ingredients are included, doesn’t mean that the products have been formulated to be effective. Your limited shower space and budget deserve more than wishful thinking in your shampoo. There are great products out there and I want you to be able to choose confidently!
With that said…
While you can find the beneficial ingredients listed above individually in many thickening haircare products, Dr. Gary Linkov’s Feel Confident signature ROOTDefense® blend includes four: saw palmetto, pumpkin seed oil, curcumin, and caffeine. The formula also incorporates panthenol (provitamin B5) and plant-based starch, which help increase the apparent diameter of the hair fiber and enhance hair body, resulting in thicker-looking, fuller hair after every wash. 30 plus years of organic chemistry experience went into developing products.
Clinically validated to reduce hair loss, support growth, and boost scalp circulation, a 12-week clinical trial and consumer perception
study found that 88% of participants observed stronger, more resilient hair and 91% improved overall hair health when using the Feel Confident Shampoo and Conditioner.
